Al-Zn-Cu系室温低Cu侧的相平衡关系

通过显微组织观察和X射线衍射分析,结合电子探针分析,确定了在Al Zn Cu系中所设计的14个不同成分的合金经充分成分均匀化和平衡阶梯冷却至20℃的合金相组成及成分·在其中11个合金中发现了T′相(Al4Cu3Zn)的存在,测定了4个合金中的T′相的成分,并得到了新的相平衡关系·从另一个侧面证实了T′相在室温时(20℃)是可以稳定存在的,同时说明美国金属学会1997年出版的相图集中的Al Zn Cu系20℃等温截面相图在低Cu侧的相关系上是不正确的·     

Our Common Responsibility： to Promote Multilateral Cooperation in S ＆ T

We are very pleased to be here to attend the Workshop on Major Challenges for Research Funding Agencies at the Beginning of the 21st century, in celebrating the 50th anniversary of the Swiss National Science Foundation. On behalf of the National Natural Science Foundation of China, I would like to extend our thanks to Prof. Diggelmann, the President, and Dr. Hertig, the Secretary General, for your ki nd invitation, as well as our warmest congratulations to the Swiss National Science Foundation, our sister organization, with whom we have worked together joyfully over 14 years, supporting many exchanges and visits, and meetings and research projects in the fields like bio-informatics and so on. It was just last June, when the Swiss Innovation Week was held in China, that two workshops were jointly supported by both foundations on the occasion.     

关于Bernestein—Trotter型算子序列的收敛定理

利用概率论的极限定理和Ｐ．Ｌｅ‘ｖｙ的连续性定理研究Ｂｅｒｎｓｔｅｉｎ－Ｔｒｏｔｔｅｒ型算子序列的极限性质，得到其收敛定理，并给出实例。     

催化动力学光度法测定痕量锰的研究

本文研究了在 PH6.4的 HAc-NaAc 介质中,痕量 Mn(Ⅱ)对过氧化氢氧化铬黑 T 褪色的新指示反应,其反应的表观活化能为63.68KJ·mol~(-1),表观速率常数 K=5.68×10~(-4)/S,半衰期T_(1/2)为20.32mm,该反应为一级反应。由此建立了催化动力学光度法测定痕量锰的新方法。本方法的 Sandell 灵敏度为4.48×10~(-7)ug/cm~2,测定范围为0～20ng/25ml。对合金钢标样和饮用水中锰的测定,结果令人满意。